Atwood MPD 93755 Installation Operation & Maintenance

Atwood
Brand
Atwood
Model
MPD 93755
Category
Water heaters & boilers
Type
Installation Operation & Maintenance

This manual is also suitable for

Atwood MPD 93755 is a water heater designed for use in recreation vehicles. It can be operated using gas, electricity, or a combination of both. The water heater has a capacity of 4.6 gallons and features an electronic ignition system for easy and reliable starting. It also has a pressure-temperature relief valve for safety. The water heater is CSA certified for installation in recreation vehicles and comes with a warranty.

Atwood MPD 93755 is a water heater designed for use in recreation vehicles. It can be operated using gas, electricity, or a combination of both. The water heater has a capacity of 4.6 gallons and features an electronic ignition system for easy and reliable starting. It also has a pressure-temperature relief valve for safety. The water heater is CSA certified for installation in recreation vehicles and comes with a warranty.

/iltAtwood'
/-a-\
Atwood
Mobile Products
LLc
(-|ESlr)
1 120 North
Main
Street
.
Elkhart, lN
4651+
\
\NrZ
/
pH'NE:
574.264.2131
FAX:
574.262.2i50
.-{il!e,/
INTERNET:
http ://www.atwoodmobile.com
LITERATURE
NUMBER
MPD 93755
L.P.
GAS
WATER HEATER
4.6.1OGALLON
Models 4-E & 10-E
EilGLISH,
FRANCAIS
(et
canada)
This
',vater
heater design has been cedified by the
Canadian
Standards
Association for installation in recreation vehicles.
This
water heater is not lor use in marine applications.
SEBVICE CALLS &
OUESTIONS
Location and
phone
numbers
of
qualified
Service
Centers can
be
found
at our
website http:/www.atwoodmobile.com or call
574-264-2131
to have a
Service Center
List mailed,
lnslallation and service
must
be
perlormed
by a
qualilied
Service
Technician, Service Center, OEM
or Gas Supplier.
olnstallation .Operation rMaintenance
Effective 04.07.09
WATER
HEATEB
MODEL IDENTIFICATION ....,..,...
,...,,......1
D|MENS|0NS ... .. . .......... 1
WEIGHT .... . .....
. . ....
. ..... 1
SAFETY |NF08MAT|0N.............
...........2-4
Water
Heater
GENERAL INSTALLATIoN .........................2-3
Wiring
Cutout Chart
Pressure
-
Temperature
Relief Valve
Consumer
Safety Warnings
...,................3
Hovr to
0perate Your Water
Heater ........... ..................3-4
lvlaintenance
and
Care
Instructions
........4-5
Preventative
Maintenance ......................5
Winterizrng
(Flushing)
lnstructi0ns ..........5
Pressure-Temperature
ReliefValve........,..... ...................5
Flushing
to Remove
Unpleasanl 0d0r...........,..
....,.........,5
FTGURES
1-12............ ..................,.6-7
PART
|DENT|F|CATT0N
.............. .....,......8
Water
Heater WARRANTY ......,,............16
EXpLANATIo\
0F tll0DEL
rrtuvern
(rxnveLr)
I I
B
Electronic
lgnition
or
Pilot Belight
I
L.+
Revision
(NUVBEB)
l->
Heating
Element (scRtw-r\
oR
BorT-oN)
4
-
6
-
10
gallon
capacity
Engine Heat Exchange
Combination
Gas and AC Electric
Gas
(enoenrur)
-
IF YOUR MODEL NUMBER IS NOT LISTED-
0lder revision
numbers may be 3, 4, 6,7, 8or
g
(_____
-
X_)
Regardless
of
your
revision number the current instructions are still
generally
applicable to
your
unit. lf
you
have
questions
contact
your
dealer, an Atwood
Service Center or the Atwood
Service
Department.
Safety Symbots..?le.
g,y0y
to
potential personal
safety hazards.
Obey all
safety messages following these symbols.
A
*o**r*c
avoid
possible
injury
or
death
A
cou,on
avoid
possible
injury and/'or
properly
damage
A
*o**,*o
FIRE OR EXPLOSION
.
lf
the
inlormation in this
manual is not lollowed
exactly, a
fire 0r explosi0n
may result
causing
pr0perty
damage,
personal
injury
or
loss
ol
Iile.
)
Do
not
store or use
gasoline or other flammable vapors
and
liquids in
the
vicinity
of this or anr other appliance.
WHAT TO DO IF YOU SMELL GAS
.
Evacuate
ALL persons
from
vehicle.
.
Shut off
gas
supply at
gas
container oI source.
.
Do
\or
touch any electrical switch, or use
any
phone
or
radio
in vehicle.
.
Do
\oT
start
vehicle's
engine or electric generator.
.
Contact
nearest gas
supplier or
qualified
Service
Technician
for repairs.
.
If you cannot reach a gas supplier or
qualified
Service
Technician,
contact the
nearest fire
department.
.
Do Nor turn on gas supply until gas leak(s) has
been
repa ired.
MODEL NUMBER
CLARIFICATION
ryPE
4 cAL 6
cAL
]
ro eal
Pilot lqnition
G4-7 eOn-Z GC6AA-8P ] etO-Z GC10A-2
Gn6AA-R GH6-7 ] cr o-zp Gn1 nA-2P
Electronic lgnition
G6A-8E GCH6A-1OE
i
GlO-3E
GCHlOA-4E
GC6AA-r0E GH6-8E I ecton-+p GHr0-3E
Pilot
Reliohl P N
ruoo$
#
-
sEE
MoDEL cLABrFrcATroN AB0VE
Heat
Exchanqe
H tH NoorL #
-
sEE
MoDEr cLARrFrcATroN AB0vE
Electronic lonilion F rN MonFr #
-
sFF MnnFr craRrFrcaroN nBnvF
Combination
Gas/Electric C N rrroo:r. #
-
sEE MoDEL cLABrFrcAroN
ABovE
DIMENSIONS
ALL MoDEL
I
*,or,
[ilt l
SHIPPING WT.
6 enrroru 25 lbs
10 cnrioru 32 lbs
6 GALLoN 1 6- 12.5'
10 GAr oN 16- 15 5-
A
c*rncAl
rNsrALLATroN
wARNTNGs
.
lnstall in recreation vehicles only. RV's
are
recreation
vehicles
designed as temporary living
quarters
for recreation,
camping, or
travel use having their own
power
or towed
by another vehicle.
.
All combustion air must be supplied from
outside the RV and all
products
of combustion must be vented to
outside the RV.
.
Do
Nor vent water heater with venting
system serving another
appliance.
.
Do Nor vent water heater to an outside enclosed
porch
area.
.
Protect building materials from flue
gas
exhaust.
o
lnstall
water
heater
on an exterior wall, with access door opening to
outdoors.
.
Do Nor modify water heater in any way.
.
Do Nor alter water heater for a
positive grounding
systern.
.
Do Nor Hl-POT water heater unless electronic ignition system
(circuit
board) has been disconnected
(DC
Hi-Pot).
.
Do Nor
use
battery charger to supply
power
to water heater
even
when testing.
USA
AND
CANADA
.
FOLLOW ALL APPLICABLE STATE AND LOCAL CODES
-
IN THE
ABSENCE OF LOCAL CODES OR HEGULATIONS,
REFER
TO CURRENT
STANOARDS OF:
.
Recreation Vehicles ANSI A1 1
9.2/NFPA 501 C.
.
National Fuel
Gas Code
ANSI 2223.1
andlor CAN/CGA B149 lnstallation
Codes
.
Federal Mobile Home
Construction & Safety Standard, Title 24
CFR,
part
3280,
or
when this
Standard
is not
applicable,
the
Standard for Manufactured
Home lnstallations
(Manufactured
Home
Sites, Communities and
Set-Ups),
ANSI A255.1
and/or CAN/CSA-2240
MH
Series, Mobile Homes.
.
National Electrical Code ANSIiNFPA No. 70
andior CSA C22.1
.
Park Trailers A1 19.5
.
CSA standard
2240 RV
Series,
Recreational Vehicle.
G
ElI ERAI ITI
STATLATIO]I
This is
a common
installation for water heaters. There
are other
approved methods such as Baggage
Compartment
(MPD
90093)
and
Flush
Mount
(MPD
93948)
installations.
Consult with
your
Field
Auditor, Account Manager, or the Atwood Service Department
if
you
have
additional
questions.
1. Locate water heater
on
floor
of coach before erecting
side walls.
The
water
heater tank must
be
permanently
supported
at the
same
level as the bottom of sidewall cutout
(by
the floor
or a
raised floor)
nc 2. Provide adequate clearance at rear of unit
for
service of
water
connections.
2. To insiall water heater on carpeting,
you
must install
appliance on a
metal
or
wood
panel
that extends at least
three inches
beyond
the
full
width and depth
of appliance.
3.
lf the
appliance
is installed where connection or tank
leakage will
damage adjacent area,
install a drain
pan (which
can be drained to
out side of coach)
under water heater.
WIRlNG
All wiring must comply
with
applicable
electrical codes.
COMBINATION GAS/ELECTRIC
M0DELS are designed to operate with
gas,
electricity, or a combination
of both.
.
Use electrical
metallic tubing, flexible metal conduii, metal clad
cable, or
nonmetallic-sheathed
cable
with
grounding
conductor.
Wire
must have a capacity of
1400 watts
or
greater.
The wiring method
must conform
to
applicable sections of article 551 of National
Electrical Code ANSI/NFPA 70.
1. Refer to Witing Diaglam
(FrG
12). Make 120 VAC
electrical
connections
from
junction
box on back of unit.
a. Connect
hot lead to
(1)
Black.
b. Connect common lead
to
(2)
White.
c. Connect
ground
wire from electrical
service
to
(3)
green ground
lead in
junction
box 3.
A cor,o*
PRODUCT DAMAGE
.
When
using
Romex@ with
a bare earth
ground,
take
care to
position
wire so it does not
contact
the heatinq
element
terminals.
.
When
a cord
and
plug
connection to the
power
supply are
used on
water
heater,
power
cord must be
UL
listed as suitable for
damp
Iocations,
hard
or extra hard usage. lt must be a flexible
cord such
as type
S, SO, SI STO,
SJ, SJT, SJTO,
HS
or HSO cord as described
in National
Electrical
Code, ANSI/NFPA 70. The length
of external
cord to water
heater, measured to face
of attachment
plug,
shall be
no less
than
2 feet nor more than
6
feet.
Supply cord must be a
minimum
of 14
AWG and attachment
plug
must
be
rated
at 15 amps.
A
cou,o*
ELECTRICAL
DAMAGE
.
Label
all wires
before disconnecting when
servicing controls.
.
Veri
operation after
servici
ELECTRONIC IGNITIOT'I
norE:
lt is recommended
unit be connected
directly
to
a
12V DC
battery or to filtered
side of an AC/DC converter. Avoid connections to
unfiltered side
of an ACIDC converter whenever
possible.
Use a
minimum
of 1B
gauge
wire. UL and
CSA
listed.
1. Refer to
Witing Diagram
(Frc
12). lnstall remote
switch in a
convenient location.
Position wall
plate
with letters up. Before
making
connections turn switch
0FF.
2. lnstall
wires see FtG 10
& 1 1.
PIL0T
RELIGHT
-
rrc
12
1. Install
unit according
to GENERAL INSTALLATION
instructions.
2. Refer to Wiring
Diagram.
Use
18
gauge
wire.
Ul-yCSA
listed.
3. Read PIL0T
& PILOT RELIGHT
0PERATIONS.
HEAT EXCHANGE
MODELS
-
no
5
1. Push
a 5/S"
diameter coolant system hose
(5-A)
lwith
SAE 053 A
Type
"E"clamp
attachedl onto heat exchanger tube
(5-B)
making
a
tight
connection.
2.
Spread hose
clamp and slide toward heat exchange unit
past
annular
groove
(5-C)
and release.
3. Continue to
HOW T0
0PERATE
Y0UR WATER HEATER and/or Electronic
lgnilion
0PERATI0N.
CONTINUE GENERAL
INSTALLATION
4.
Connect bolh
1/2" NPT water lines
(rro
2) hot water outlet female
and cold water
inlet female and 3/8"flared LP
gas
line to the water
heater
(rrc
9).
a.
Allow
flexibility in water
and
gas
lines so
you
can
pull
unit
forward
through wall
one
inch
past
skin.
b. Seal
gas
line
entrance opening
(rtc
9) by
sliding
grommet
(9-B)
onto 3/8" tubing
(9-D)
before
flaring tubing
(9-E).
Pull
gas
line and
grommet
through
opening
in housing
(9-A).
Connect flare fitting
(9-C)
and
press grommet
into opening. lf
gas
line tubing is
already flared,
cut
grommet
on one side.
Place
split
grommet
over
gas
line and
press
it into opening.
c.
Always
use
pipe
lubricant on threads when connecting
hot
and
cold water
couplings.
A
suitable
plastic
fitting is
recommended.
CAUTION
DAMAGE
.
Do
not lift,
pull, push
or misalign main burner
tube
(rtc
3-F).
5. Erect
side walls and cut opening.
See
chart and
FrG 1.
Frame with
2x2 lumber
(or
equivalent).
CUTQUT(Frcl&2)
CAPACITY
CUT OUT DIMENSION DEPTH
Gallon
4-O
'10
1-A
12-5/g
1-B 2-C
16-1
/4'
15-3/4' 16-1/4'
MINIMUM
CLEARANCE FROM COMBUSTIBLE CONSTRUCTION
Sides: A' Top: U'
Back: U' Bottom: tr
6.
Bend
all flanges
90" along scored lines
(rto
3-A).
7. To
prevent
water
leaks caulk thoroughly around opening, including
bend slots. Butyl
Tape
(1-1/5'x1/8)
may be substituted for caulking
material.
I /
-5/d
20-5/8"
B. Push unit against
caulking. secure
4-corner brackets
(rto
3-B) to
coach
with No. 8
-
3i4"
round head screws
(not
furnished) or equivalent.
Complete
the installat on
by inserting the same type of #8 screws in the
holes
provided
around
the.lange of the water heater housing.
Check all
gaskels.
they must adhere
t0 the
pan
crealing an air tight
seal.
9.
Attach
access
doc..
a. Snap
hinge c
r-
=
,
3-Ct into clip
(rtc
3-D).
b.
Slide
co\,e'
::
-1-I
onto hinge
pin.
c, Sllie hirge c
- -:o
cover, snapping into clip at same time
(rtc
3-D).
uorE: To rerc. a
-
-ge
oin.
support access cover
and apply
force to
corre. ci
t-
'ge oin.
10. Discc^:e:: ..i^ t a1d
lts individual shut-off valve from
gas
supply
line c-'i^g
a.i
pressure
testing of system
in
excess of
1/2 PSIG
(3.:
<Pa.
-r
'.','ater
column
[W.C.]).
oo Nor set inlet
pressure
higher
tl^a.
rax
.rum
indicated on rating
plate
of
gas
valve
(1
3" W.C.).
lso a::
--
t
from
gas
supply
line by closing its individual manual
sri:ci:
',
arve during any
pressure
testing
<
1/2
psig.
1 1. Turn on
gas
and check
water heater and all connections
for
gas
leaks lvith leak detecting solution.
'1
2. Fil rvater heater
tank,
check
all connections for water ieaks.
PRESSURE-TEMPERATURE
RELIEF
VALVE
THIS VALVE IS A
SAFETY
COMPONENT
AND MUST NOT BE HEMOVED FOR ANY BEASON
oTHER
THAN BEPLACEMENT. This water
heater is equipped with a
temperature and
pressure
relief
valve
(rtc
3-G) that complies with
standard
for Relief Valves and
Automatic Gas Shutotf Devices
for Hot
Water Systems,
ANSI 221.22.
lf
you
use a discharge
line, do not use a
reducing
coupling or other
restriction smaller than outlet
of relief
valve. Allow
complete drainage
of both
valve and line.
FOR
REPLACEMENT PARTS:
.
Do Nor install anything
less than a combination
temperature-pressure
relief valve certified by a
nationally
recognized testing laboratory that
maintains
periodic
inspection of
product
of llsted equipment or
materials, as
meeting requirements
for Relief
Valves
and
Automatic
Gas Shutoff
Devices for Hot
Water Supply Systems, ANSI 221
.22.
Valve must have a
maximum set
pressure
not to exceed 150
psi.
.
Install valve into opening
provided
and marked for this
purpose
on
water heater.
.
lnstallation
must conform
with local codes or in the absence of
local
codes,
American National Standard
for Recreational Vehicles,
ANSI
41 19,2/NFPA 5OIC.
.
For
an external
electrical source,
ground
this unit in accordance
with
National Electrical Code
ANSI/NFPA70.
Your ATWOOD PIL0T GAS WATEB
HEATER is now ready for operation.
Continue
to HOW T0
0PERATE
Y0UR WATER
HEATER
HOW TO
OPERATE
YOUR WATER HEATER
A
cournon
lf water heater
has not been used
for more than two weeks, hydrogen
gas
may form
in water line. Under
these
conditions
to reduce the risk
of injury,
open hot water faucet
for
several
minutes at kitchen sink
before
you
use any electrical appliance connected
to hot water system.
lf hydrogen
gas
is
present, you
will
probably
hear sounds like air
escaping through the
pipe
as water begins
to flow.
WARNING
NG INJUBY
o
Do
not tamper with
pilot
orifice.
CAUTION
PRODUCT
FAILURE
.
Do not
operate without water
in tank.
PILOT OPERATION
1. Water
heater may be equipped
with a White Rodgers@ or
Robertshaw
Unitrol@ Control rro
7.
2.
Turn
gas
control valve knob
(rro
7-B)
to
OFF
position.
3. Wait at least five
minutes
to
allow
accumulated
gas
in
burner
compartment
to escape.
FOR WHITE
RODGERS'CONTROL
(rro
7)
a. Turn iighting
control
knob
(7-B)
to PILOT
position
and
hold
against
stop while lighting
pilot
burner.
b. Allow
pilot
to burn thirty seconds then release
lighting
control
knob.
c. Turn lighting
control knob
(7-B)
to
0N
position.
d. lf
pilot
does not remain lit,
repeat
operation allowing
longer
period
before releasing lighting control
knob.
e.
Set
temperature
selection lever
(7-A)
at
mark between warm and
hot
position.
f.
Close access door.
A *o*N,nc
.
ra
',1-
use
matches,
candles
or oiher sources of
ignition when
GO]ISUMER SAFETY WARNI]IGS
WARNING
EXPLOSION
OR
.
Do Nor
store or use
gasoline
or other flammable
vapors and liquids in
the vicinity
of this or any other appliance.
.
Should overheating occur, or
gas
supply
fail to
shut
off, turn OFF
manual
gas
control valve
to
appliance,
or turn
gas
0FF at
the LP
tank.
On
ELECTR0NIC
lGNlTl0N
M0DEL turn operating switch
to
OFF
position
and remove red wire
from left hand terminal of ECO switch
or turn
gas
OFF at the LP tank.
.
Use with LP
gas
only.
.
Shut off
gas
appliances and
pilot
lights
when refueling.
.
On PIL0T RELIGHT
MODELS,
turn off the ignition
module when
refueling
gasoline
tanks or LP
tanks.
.
Turn
gas
OFF at the LP tank when
vehicle is
in motion. This disables
all
gas
appliances and
pilot
lights. Gas
appliances
must never be
operated
while vehicle is in motion. Unpredictable
wind currents
may
be created which could cause flame
reversal in the burner
tube.
which
could
result in fire damage. The
thermal cut otf fuse
could also be
unnecessarily activated
resuliing in a complete
shutdown of the
water heater requiring
replacement of the thermal
cut off, See
maintenance of electronic
ignition water heaters for
further
explanation
of the thermal cut off.
.
LP tanks must
be filled by a
qualified gas
supplier only.
WARNING
EXPLOSION
.
Valve is not serviceable,
it must be replaced.
.
Tampering with valve
will result in scalding
injury.
.
Tampering with valve
will void warranty.
.
rc Nor
place
a valve,
plug
or
reducing coupling on outlet
part
of
relief valve.
FOR A ROBERTSHAW
UNITROL@
(rro
7)
a. Turn lighting
control dial
(7-B)
to
PILOT
position.
b. Depress
and hold reset
push
button
(7-A)
while lighting
pilot
burner
(7-C).
c.
Allow
pilot
to burn thidy
seconds
before releasing reset
push
button.
d. lf
pilot
does not remain lit,
repeat
operation allowing
longer
period
before releasing
reset
push
button.
e. Turn
lighting control
dial
(7-B)
to
0N
position.
f.
Set temperature
control dial
(7-C)
at mid-point
position
between
warm and hot.
g.
Close access
door.
4. For
complete shut down
and before servicing,
turn
gas
control knob
(rro
7-B) to
OFF
position.
When water heater
is not in
use set
temperature
control lever
(White
Rogers@)
or dial
(Roberlshaw@)
to
lowest
possible position.
WARN!NG
SCALDING INJ
.
Setting temperature
control dial at a higher
position
will
produce
excessively
hot water.
The temperature
knob or lever is factory
adjusted
to its lowest
dial
setting. We recommended
the mid-point
position
between warm
and
hot, as noted
above. This will
provide
for energy
efficient
operation
and sufficient hot water.
Valves for reducing
point
of use temperature
by mixing cold
and hot water are
available.
Consult a licensed
plumber
or local
plumbing
authority.
5. To Adjust Main Burner
(rrc
4):
1. Loosen
air shutter
screw
(4-A).
2. Slide air shutter
(4-B)
to right until
some
yellow
appears in main
burner flame.
3. Move air
shutter
(4-B)
to left until
yellow
disappears.
4. Retighten
air shutter screw
(4-A).
Read
MAINTENANCE AND
CABE INSTRUCTI0NS
ELECTRONIC
IGNITION
OPERATION
1. Refer
to WIRING DIAGRAM rrc 12.
Place remote
switch in
0N
position.
2. lf remote
switch light stays on longer
than 15 seconds.
place
remote
switch in
0FF
position
and wait 5 minutes.
3. Repeat step one.
4. For
complete shut-down and before
servicing:
a.
Place
remote switch in
0FF
position.
b. Remove red wire from left
hand terminal
of
ECO
switch
(ECO
to
valve).
5.
lf
heater fails to operate due to high
waier temperature.
a lockout
condition occurs
(indicator
light
on). After water
cools. reset switch
in
OFF
position
for at least 30 seconds, then
turn to 0N
position.
6.
lf
a lockout condition
persists
contact
an Atwood
Service Center.
Read MAINTENANCE AND
CABE INSTRUCTI0NS & ELECTH0NIC
lGNlTl0N
MAINTENANCE
PILOT RELIGHT
OPERATION
1. Turn the switch located
on the spark module to the
0N
position.
2.
Read PILOT
0PERATI0N
instructions.
3. For complete
shut down, turn llghting
control knob
on
thermostat
and
spark module switch to the
0FF
position.
Read MAINTENANCE
AND CARE INSTRUCTIONS
GAS/ELECTRIC
COMBINATION FUNCTION
GAs 0PERAT|0N. When the
gas
switch is turned
on, the
unit will make
three
attempts to light.
lf for any reason
there is no ignition,
the
unit will
lockout
and
the
red lockout lamp
will illuminate.
lf the thermostat
fails,
the ECO will
also lockout the
unit, requiring resetting.
Determrne
the
reason
for no ignition,
correct it, and reset the
gas
ignition
sequence
by turning the switch
off, then on.
ELEGTRTC
0PERAT|0N. When the electric
switch is turned
on, the relay
at the
rear
of
the
unit will close
and
pass
110vac to the
element. lf the
thermostat
were to fail, the ECO will
open and lockout
the
system. To
correct,
check the thermostat to
assure
good
contact with the
tank
and reset the
control by turning the
electric switch
off, then
on.
GAs/ELEcrBrc
opERATroN.
The
unit can be run in
both
gas
and electric
modes
simultaneously
for
quick
recovery.
note: if the
gas
fails
to
ignite,
the
gas
mode will lockout.
but the
Iockout
lamp will
not
illuminate
since the
electric mode is
still operational.
Should
you
notice
slow recovery,
indicating
the
gas
is not
working,
turn the
electric
switch
off. The
lamp will
ihen illuminate
indicating
a lockout
has
occurred
on
the
gas
side. Correct the
problem
and turn the
switches
back
on.
Read
MAINTENANCE
AND
CARE li{STRUCTI()NS.
MAIIITEIIAI{GE
A}I D
GARE I]{STRUGTIO]IS
SERVICE
CALLS
&
OUESTIONS
Location
and
phone
numbers
of ota,ified Service
Centers
can be found
at our website
http:/www.atwoodmca
e.com
or call 574-262-2655
to
have
a Service Center List mailec.
The
use of
any aftermarket
heating e 3-:-:
damage
to
components
or water
heale.
:
states -
"failure
or damage resulttng
'.:-
,
heater
is
the owner's
responsibiliti" .
:-_.
an
aftermarket
heating
element de'.'::
,,,
GENERAL INFORMATION
.
LP
and Water
system
must
b:
'.-.'=.
-^
.
Have
gas
pressure
tested
pe'
.. :z
.
S-c
-
: :: set at 1
I inches
of
water
column
with three app a-::-<
'-"':
.
Drain
water
heater at regula'
^::',:
-.
a:
:as: 3.e time
during the
year).
.
Drain
water
heater before sic.
^:
=.
':,
:-e
,,,,tnter
or when
the
possibility
of freezing exists.
.
Keep
vent and
combustior, e'
j'
:
=ar
of any
obstructions.
.
Periodically,
compare flar.'e c'
-a
-
and
pilot
burners with Ftc
5 and
main
burner
adjustments
:
HoW
T0
oPERATE Y0UH WATER
HEATER.
.
When
water
heater is
noi
,"
-se
se: temperature
control lever
(White
Rogers)
or
dial
(Robertsha',,,,
:c
.c''vest
possible
position.
This
will
reduce
the
effects of lo',,, cJ:Coor temperatures
on calibration
of
temperature
control Tnec-a':,sm:
ELECTRONIC
IGNITION MAINTENANCE
.
The
water heater
comes factory-equipped
with a fused
circuit board,
which
will
protect
the circuit
board from wiring shorls. lf the fuse
should
activate, the v,,aier
heater will not
operate. Before replacing
the fuse,
check for
a shod external to the
board. Once the
shod is
corrected,
replace
the 2 amp
fuse with a mini ATO
style fuse. Do nol
install
a fuse
larger than
3 amps.
o
lf
the fuse
is
good
and the
unit
is inoperative,
check for
excessively
high voltage
to
the unit
(more
than 14 volts).
.
lf the
previous
two steps
did not solve the
problem,
check the
thermal
cut-off
(Ftc
3-l). The thermal
cutoff
is
a device installed
in the
power
supply
line. This
device will shut off electrical
power
and stop
heater
operation
when
activated. For example, if
an obstruction
within
the flue
tube
should occur, as described in
the Preventative
Maintenance
section,
the burner flame/heat may
contact the
cutoff,
resulting
in
a melting of the fuse
element incorporated in
the
thermal
cutoff.
In order to restore
power
and
proper
operation of the
water heater,
the
obstruction must
be removed and the thermal
cutoff must
be replaced.
-a;,
also
result in
':ie1
warranty
:i :c
our water
<= :rie
addition
of
,J=
=
L)
WABNING
FIRE
OR EXPLOSION
.
Shut
off
gas
supply
at
LP
containe. ::'cre disconnecting
a
gas
line.
.
Keep
control
compartment
clear :-:
'.ee
of
gasoline,
combustible
material,
and flammable
liouids a-c
.acc!"s.
AFTERMARKET
WATER
HEATING ELEhIENT
DEVICES
A *o**,*o
IXJURY
.
Do
Nor alter
water heater,
it will void :,a:-?'::
.
Do Nor
usr
Aftermarket
heating eler,re s :-3,. :-a-
a:x critical
safety
controls.
.
Use of Aftermarket
heating eleme":s .?' :.-:::
a- out
of control
heating
of water
tank and a catas:.:3- : ,,,::
s :=
=rclosion.
PREVEI{TATIVE
MAI NTEI{AI{GE
Spiders,
mud wasps, and other
insects
can build
nests in the
burner
tube. This will cause
poor
combustion, delayed ignition or ignition
outside combusiion
tube. Listen for a change
in
burner sounds or in
flame appearance
from a hard blue flame to a soft lazy flame or one
that is very
yellow.
These are indications of an obstruction in burner
tube
(rrc
4-C). lnspect and clean on a regular basis.
a.
Remove air shutter screw
(rro
4-A) and slide air shutter
(rrc
4-B)
dorvn burner
tube.
b. Run a
flexible wire
brush down
burner tube
(no
4-D) until it is
visible
at
end of burner tube.
c.
Vacuum burner where it enters combustion
tube.
d. Retum air shutter to original
position
and
replace
screw.
e. The orilice, burner
tube and shutter must be aligned s0 that the shutter is nol
binding on
the air tube.
HOW T0
CLEAN
PIL0T M0DELS
-
rte s
1.
Check
main burner orifice and
pilot
assembly for contamination
(dirt,
spider
webs,
etc.).
2. Clean main burner
tube with small brush.
3.
Main
burner
adjustment
-
open air shutter
1/4 way.
4. Low
pilot
flame. Check
for contamination
-
if clean have the
pilot
orifice replaced.
HOW TO CLEAN
ELECTRONIC IGNITION MODEL
1.
Check
main burner orifice.
2. Clean and ad.just main burner.
3. Main burner and
valve manifold must align with each other
4.
Check electrode
for cracked
porcelain
(rrc
4-E).
5. Check electrode for
proper gap
-
1/8"
between electrode and
ground.
6. lf module board
functions intermittently. remove board and clean
terminal block
with
pencil
eraser
(nc
3-H).
WATER HEATER TANK CARE
WARNING
SCALDING
INJURY
.
Turn off water heater and allow
time for water to
cool
before
inq drain
pluq
to flush tank.
wtl{TERtZtl{G
(FrUSHrilG}
rI{STRUCTT0ilS
To insure the best
performance
of
your
water heater and add to the life
of the tank,
periodically
drain and
flush the water heater tank. Before
long term storage or freezing
weather drain and flush the tank.
1. Turn
off
main water supply
(the
pump
or water supply
(the
pump
or
water hook up source).
2. Drain Water
Heater Tank by removing
the
drain
plug-
lf the water
flows sporadically or
trickles instead of a steady stream of
water, we
recommend
the following action:
first
open
the Pressure
Temperature Relief
Valve to allow air
tnto the tank
and secondly,
take
a
small
gauge
wire
or
coat hanger and
poke
through
the
drain
opening to eliminate any
obstructions.
3.
After
draining
the tank, because
of the
placement
of the Drain
Plug,
approximately
two
quarts
of
water will remain in the tank. This
water
contains
most of the harmful corrosive
particles.
To remove these
harmful corrosive
particles
flush the tank with either air or water.
Whether using air or
water
pressure,
it may be applied through
the
inlet or outlet on
the rear of the tank or
the Pressure
Temperature
Relief Valve.
(lf
using
the Pressure Temperature Relief Valve the
Support Flange
must
be
removed). The
pressure
will force out the
remaining
water and
the corrosive
pafticles.
lf
you
use water
pressure, pump
fresh water into the tank with the
assistance of the on-board
pump
or use external water
for
90
seconds to allow the fresh water to agitate the stagnant water on
the bottom of the tank and force deposits
through
the drain
opening.
Continue
repeating adding water and draining until the
particles
have been cleared from the water remaining in the tank.
4. Replace the Drain Plug
and close
the Pressure Temperature Relieve
Valve. the approximately
two
quarts
of
water remining in the tank
after
draining will not cause damage
to the tank
should
freezing
occur.
PRESSURE.IEMPERAIUBE
RETIEF UATVE
WARNING
EXPLOSION
.
Do not
place
a valve,
plug
or reducing coupling on outlet
part
of
pressure-temperature
relief valve.
A Pressure Temperature
Relief Valve, dripping while the water heater is
running,
DOES
NOT mean it is defective. During normal expansion of
water,
as it is heated
in the closed water system of a recreation
vehicle,
the Pressure
Temperature Relief Valve
will
sometimes drip. The
Atwood
water heater tank is
designed
with
an
internal air
gap
at
the
top of the tank
to reduce the
possibility
of dripping. ln time, the
expanding water
will absorb this air and it must be restored. Due to
variations
in water
quality,
the
Pressure
Temperture Relief Valve may
have
a shorter life
and
may need replacement within the water heater
warranty
period.
lf corrosion is detected, it will not be covered under
warranty.
A wonr,nc
SCALDING
INJURY
.
Turn off water
heater before opening
pressure-temperature
relief
valve to establish
air space. Storage water
must
be
cool.
TO REPLACE THE AIR
GAP
FOLLOW THESE
STEPS:
1. Turn
off main water supply
(the
pump
or water hook up source).
2. Let water
cool or let run until cool.
3.
Open
the
hot water faucet closest to the water
heater.
4. Pull handle
of
pressure
temperature relief
valve
straight out and
allow water
to flow until it stops.
5. Allow
pressure
temperature relief valve to snap shut; close
faucet;
turn on water
supply.
6.
Turn
on water heater
and
test.
.
At least
once a
year
manually operate
pressure-temperature
relief
valve (rrc
16).
When
pressure-temperature
relief valve discharges again,
repeat
above
procedure.
For
a
permanent
solution, we recommend one of
the following:
.
lnstall
a
pressure
relief valve in cold water
inlet line to water heater
and attach
a drain line from valve to outside of coach. Set
to relieve
at 100-125
PSl.
.
lnstall a
diaphragm-type expansion tank in cold
water inlet line. Tank
should
be sized to allow for expansion of approximately
15
oz. of water
and
pre-charged
to a
pressure
equal to water supply
pressure.
These
devices can be
obtained
from a
plumbing
contractor or service center.
FTUSHII{8 IO
REMOVE UNPIEASAI{T ODOR
A rotten egg odor
(hydrogen
sulfide)
may be
produced
when the electro
galvanic
action
of the cladding material
releases hydrogen from the
water. if
sulfur is
present
in the water supply
the two will combine and
produce
an unpleasant smell.
1. Turn
off
main
water supply. Drain the
water heater tank and reinstall
drain
plug.
Remove the
pressure-temperature
relief valve. Mix
solution
of 4
parts
white vinegar
to two
parts
water. With a funnel,
carefully
pour
solution
into tank.
2. Cycle water
heater with
the
above solution,
letting
it run
under
normal operation
4-5
times.
3. Remove the
drain
plug
and
thoroughly drain all water
from the tank.
Flush the water
heater to remove any
sediment. You
may flush the
tank with
air
pressure
or
fresh water.
pressure
may
be applied
through
either the inlet or outlet
Valves on the rear of
the tank
or
through the
pressure-temperature
relief
valve coupling
located
on
the
front
of
the
unit.
TO FLUSH
TAN( WITH AIR PRESSURE:
lnsed
your
air
pressure
through the
pressure-temperature
relief
valve
coupling. With the
drain
valve open, ihe air
pressure
will force
the remaining
water out of the unit.
To llush lank with
water
pressure:
Fresh
water
should be
pumped
into the tank with either the
onboard
pump
or external water
pressure.
Continue
this flushing
process
for
approximately 5 minutes, allowing
the fresh water to
agitate the
stagnant water on the bottom of
the tank
and
forcing
the deposits
through the drain opening.
4. Replace
drain
plug
and
pressure-temperature
relief valve.
5. Refill tank with
fresh water that contains
no sulphur.
The Atwood
water heater is designed for use
in
a
recreation vehicle. lf
you
use
your
vehicle frequently
or
for long
periods
of time, flushing the
water
heater several times
a
year
will
prolong
the life of the storage tank.
Hot Water
0utlet4
Cold
Water
lnlet\
1'
'J_/"
A
0
6 GAtLOil
BUCK
TO ELEMENI
GREEN GROUP
TO STUD
NOT
BUCK
USED
llOVHOT
\1
i1
.,1 L
t1
@la
_r_t
l
'a@i4
-^|_
l
o-T---F@
I
---]l
t-'i'l
-\.O
-li
i
n-t==--t .
.-.=\
)
i,,zt l
i'9 l
.S_,
--
l
Y
---l-------
'l
\@tr-:-A
\\
u
I
.=4)-l
@
t,*ntE swtTGH
--
c-\
Dotted
!!nes
are
wlred by
gystomer
COMBIilATIOl{
GAS/EtEGTRIG
BLUE FROi',1
'Ji
-
(L0cK-0uT
rAMP,
+1
2 VDC
GAS- ORANGE FROI\,4 WH
ELEC
-WHITE
FROI\4 WH,
BLANK 4
----
-r@rr-\-
REMOTE
swtTcH
*lz
4
j
wc
+/e
ELECTRIC
+1 2 VDC
WHITE FROIM W.H.
(ELECTRIC)
GREEN FROIV]
W.H,
(GROUND)
Dotted lines are
wired by customer
PII.OT
RETIGHT
Switch
(
1
)-BLACK ..' BLACK
.--
I
o
(
3
)-GBEEN
Ground
[r,
rireO Thermosrat
-(2)-wHrrE
,.
BLA0K
?
11lanuarReset
.g\''/\r--
Erement
l'flll'#,or'|l'n'"
CBEEN
RED
Ho!
leqq
Gf9!'!q
lgqq
Common Lead
High Voltage Lead
t0
Burner Electrode
11llv ELECIBIG/GAS PITOT
Ol{tY
RETIOTE
LOCK.OUT
LAHP
.-
1t5V
I{EURTAL
FIXED TEMP
CONT T-STAT
THERMAL
CUT-OFF
U}fT
1 15Y
HOT
JUMPER WIRE
JUMPER WRE
@
wrnrilG
DTAGRAMs
GRH
GREEN
PART
IDENTIFICATION
/
IDENTIFICATION DES
PIECES
PILOT
IGNITION
/
PILOT
RELIGHT
ALLUMAGE
DE VEILLEUSE
/
RALLUMAGE
DE
VEILLEUSE
SPARK
IGNITION
/
HEAT
EXCHANGE
ALLUMAGE
PAR ETINCELLES
/
EcHRHor
DE cHALEUR
GAz-
REFERENcE
22 rrrR=s
38
rtrnes
PILOT
IGNITION
AILUIIAGE
DE
rElllEgSE-
2
90960
3
91857
4
91604
90028
5
91602
6
92615
7
91603
8,/
x
90960
91 857
91
604
90028
91
602
93221
91 603
*Tank
Flue
Box Assembly
Drain
Plug
(shown
on
spark ignitiont
1/2 NPT
Pressure-TemP
r:
:'
,:
3i4" NPT
Pressure-Terc.=:
:'
.:
.=
Thermostat
Main Burner
Pilot
Assembly
Exterior
Access
Door
=,:
.' ." conduit
::-:-c^
de
vidange
-'
a rmage
6lectronique)
S:
-:ape
de d6charge
de
tYPe
S:-cape
de d6charge
--e.mostat
3'-,eur
principal
. e leuse
-'appe
d'accds
ext6rieur
PILOT
RELIGHT
RALLUMAGE
DE VEILLEUSE
I
10
IO
93801
93804
93803
93801
93804
93803
Spark
Module
Electrode
Assembly
Wiring
Harness
l,4odule d'allumage
Electrode
Faisceau 6lectrique
SPARK
IGNITION
ALLUMAGE
PAR
ETINCELLE
1
2
3
4
o
11
12
13
16
17
x
90960
91 857
91 604
93844
91
959
91 859
93851
931
91
93866
93868
91447
x
90960
91
857
91
604
93844
91 959
91 859
93851
931
91
93866
93868
91447
*Tank
Flue Box
Assembly
Drain
Plug
Pressure-Temperature
Fe
3'
,:
.:
Solenoid
Valve
Black on-Off
Switch
White On-Off Switch
Circuit
Board
Wiring Harness
Thermal
Cut
Off
Spark
Probe
Thermostat/ECO
R6servoir
Boitier
du conduit
Bouchon
de
vidange
Soupape
de decharge
de
tYPe
Electrovanne
lnterrupteur
Marche/Arr6t
noir
I nterrupteur
Marche/Arr6t
blanc
Circuit
imprim6
Faisceau 6lectrique
Coupure
thermique
D6tecteur
d'6tincelle
ThermostaVECO
HEAT
EXCHANGE
Ecxance
DE
cHALEUR
*Tank R6servoir
COMBINATION
GAS/ELEGTRIC
GAZ
-
ELEGTRICITE
COMBINES
.,1
NS
NS
X
92249
93849
x
92249
93849
*Tank
Heating
Element & Gasket
Relay
R6servoir
El6ment
de
chauffe
ei
ioint
Relais
*
x
All tanks
includes styrofoam
jacket
=
Tous
les r6servoirs
comprennent
une chemise
de
polystyrene.
Order
by
model
=
Commander selon
le moddle
Order by
color
=
Commander
selon
la
couleur
8
  • Page 1 1
  • Page 2 2
  • Page 3 3
  • Page 4 4
  • Page 5 5
  • Page 6 6
  • Page 7 7
  • Page 8 8

Atwood MPD 93755 Installation Operation & Maintenance

Atwood
Brand
Atwood
Model
MPD 93755
Category
Water heaters & boilers
Type
Installation Operation & Maintenance
This manual is also suitable for

Atwood MPD 93755 is a water heater designed for use in recreation vehicles. It can be operated using gas, electricity, or a combination of both. The water heater has a capacity of 4.6 gallons and features an electronic ignition system for easy and reliable starting. It also has a pressure-temperature relief valve for safety. The water heater is CSA certified for installation in recreation vehicles and comes with a warranty.

Download PDF
report

Ask a question and I''ll find the answer in the document

Finding information in a document is now easier with AI

Related papers

Other documents